The nation's two largest airlines raised the stakes in a spreading summer fare war today, extending discounts of up to 50 percent to all domestic flights and promoting the sale an additional week.
The promotion by American and United, which lasts until April 14, followed Northwest's announcement Thursday of a fare sale in some cities through April 7.
USAir, Trans World Airlines, Delta and Continental said they would offer fares in markets where they compete with Northwest.
American and United said they would apply the discounts in all domestic markets, not just where they compete with Northwest.
Under the sale's other conditions, passengers must fly Tuesday, Wednesday or on Saturday afternoons between May 1 and Sept. 14 to get the full 50 percent discount. Discounts will be less at other times.